FIG. 1 shows a conventional photovoltaic cell 1. Photovoltaic cell 1 comprises a planar semiconductor material 3. Material 3, generally made of polysilicon, comprises three areas of different doping. A thick central area 3a is lightly P-type doped. An upper area 3b is N-type doped, and possibly overdoped at its surface. A lower area 3c is heavily P-type doped (P+). A conductive comb 5 is placed above area 3b, intended to be exposed to light. An aluminum layer 6 covers the lower surface of the cell. Comb 5 and layer 6 are both intended to transmit the photovoltaic current and are connected to the + and − terminals, not shown, of the cell. An antireflection layer, not shown, is preferably placed on area 3b and comb 5 to limit the reflection of light rays at the photocell surface.
Material 3 conventional originates from a polysilicon bar obtained from a silicon melt. The bar is sawn to obtain wafers which are then doped to obtain material 3. This manufacturing method, close to the single-crystal silicon wafer manufacturing method, is expensive and limits the possible wafer dimensions.